The outside world must help Iraqis turned into refugees, and prevent the
creation of an Islamist semi-state

Islamic State is a serious threat, and one that has to be confronted. Its outlook is medieval, even half-crazed: to destroy all other faiths, impose Sharia and establish a caliphate. Yet its military successes have been extraordinary – spreading across Syria and Iraq like a plague, threatening Baghdad and pushing towards the Kurdish homeland. This advance has driven thousands of Christians, Yazidis and other religious minorities from their homes under the threat of “convert or die”.

The result is a humanitarian crisis in Iraq, a threat to the stability of the region and a challenge to Western security. A spokesman for Islamic State has promised to “humiliate” the United States and to “raise the flag of Allah in the White House”. The ranks of this terrifying army include foreign fighters: the Americans calculate that around 3,000 of them may hold European passports.

The immediate reason why the outside world has to intervene in some form is to help those turned into refugees, trapped perilously between the threat of execution and the threat of dying in the harsh geography of Iraq. We also have a debt to pay: as General Sir Richard Dannatt argues, the invasion of Iraq in 2003 helped to create some, if by no means all, of the conditions for Islamic State’s rise.

But, clearly, there is also a wider task facing the West, of preventing the creation of an Islamist semi-state that both destabilises the nations around it and provides a safe haven for the plotting of terrorist attacks elsewhere. It is against this backdrop that the US has started air strikes to halt the advance of the jihadis, with Britain providing limited support.

This operation has to strike a careful balance. Act too timidly, and we may fail to provide sufficient help to those we seek to assist. Get too involved too quickly, and our Armed Forces may be sucked into an unwanted conflict which could potentially make the West an even greater target for terrorist outrages in the future.

In military terms, the situation will have to be very closely monitored to decide whether what we are doing is working and, if not, what should be done instead. Barack Obama has indicated that he sees this being a “long-term project”, and one in which the Iraqis themselves must take a lead.

Where our action should certainly be unstinting is in the provision of humanitarian aid, and the US and Britain will hopefully do their best to help those requiring water and supplies. Douglas Alexander, the shadow foreign secretary, notes that the Catholic Bishops’ Conference of England and Wales has designated today a day of prayer for the people of Iraq, while Archbishop Justin Welby has spoken of an “evil pattern around the world” whereby religious minorities are persecuted for their faith.

Certainly, the conscience of the West has been pricked by these terrible events – and rightly so. No country should be too far away for its suffering not to touch our hearts. Nor, in this turbulent age, is any conflict so distant that it will not eventually affect the safety of those of us at home.